Electrolytic cell



E. B. CUTTEN.

ELECTROLYTIC CELL.

APPLICATION FILED JUNE 25. 1920.

2 .SHEETS-SHEET 2.

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Patented Nov. 22, 1921.

ELISHA BARTON CUTTEN, 0F MINNEAPOLIS, MINNESOTA.

ELECTROLYTIC CELL.

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Application filed June 25, 1920.

To all whom it may concern: k

Be it known that I, ELISHA B. Curran, a citizenflof the United States, and a resident of Minneapolis, county of Hennepin, State of Minnesota, have invented certain new and useful Improvements in Electrolytic Cells; and I do hereby declare the following to be a full, clear, and exact description of the 1nvention, such as will enable others skllled in the art to which it appertains to make and use the same.

The invention relates to an electrolytic cell more particularly adapted to the decomposition of a sodium chlorid solution, with the formation of chlorin and hydrogen which are taken off in gaseous form and the formation of sodium hydrate or caustic soda. The invention has for its object to provide a simple and efficient form of apparatus in which the internal resistance of the cell Wlll be maintained at a low minimum, the collection of deposits of impurities tending to impair the action of the device will be obviated and'the several products resulting from the eletrolytic actionto-wit, chlorin gas, hydrogen gas, and a strong solution of caustic soda-may be severally recovered and may be drawn from the apparatus in a comparatively pure condition.

The apparatus is illustrated in the accompanying drawings, in which Figure 1 is a sectional elevation of one of the cells;

Fig. 2 is an enlarged sectional elevation of the support and connecting means for the anode;

Fig. 3 is anenlarged fragmentary sectional elevation of the casing and the foraminated lining therefor.

Referring to the drawings 1 indicates a tankor vessel preferably made of iron and constituting the cathode member of the cell, said tank being provided with a conical bottom 2, which projects inwardly of the tank and serves as the primary support for the anode. The interior of the tank is provided with a liner 3, which is formed as a cylinder of sheet iron, having an imperforate upper section provided with a marginal flange which is connected to the upper rim of the tank by a hermetic seal, formed preferably by welding the flange of the liner to the rim of the tank thereby forming an annular Specification of Letters Patent.

Patented N av. 22, 1921.

Serial No. 391,614.

chamber between the tank walls and the imperforate section of the liner. The major portion of the liner is perforated by means of a multiplicity of V-shaped openings formed by punching out generally triangular tongue members 4 which are bent outwardly in the punching operation and engage in the inner surface of the wall of the tank 1. The said liner 3 extends to near the bottom of the tank and provides an annular chamber or,

channel about the inner Walls of the tank from the top to the bottom thereof to facilitate the movement of the heavier products of the electrolytic action toward the bottom of the tank and a concurrent movement of certain of the lighter products and wash water toward the top of the tank, as will be more fully explained hereinafter.

Also secured to the upper rim of the tank, and connected thereto by a fluid-tight joint, as by electric welding, is anannular partition plate 5 having a horizontal flange 6 which may overlie the flange connecting the liner 3 with the rim of the tank. Said partition plate is preferably formed by sheet iron or other appropriate material coated .with a chemical resisting medium such as japan,

varnish, enamel, or the like so that the paror any of the products evolved therefrom. T he partition 5 is of sufficient length, so that its lower edge is well submerged in the electrolyte and forms an annular chamber to receive the gas freed at the cathode, said gas being prevented from escaping from the chamber by the liquid seal formed by the immersion of the lower end of the partition 5 in the electrolyte. A discharge pipe 17, provided with a suitable valve, communicates with the annular chamber aforesaid and affords means for drawing oii the gas which accumulates in the chamber. "To facilitate the discharge of the gas, the pipe 1.7 is preferably connected with a pumpor other exhaust apparatus which will induce a steady fiow of the gas from the chamber.

Mounted on top of the tank is a spiderlike ring 11 which serves to support a generally bell-shaped dome or receiver 8, made of glass, stone-ware or other suitable material, which is not affected b, the electrolyte or the reaction products. aid receiver extends wellwithin the outer tank 1 and. is

member 14 made of similar material to that of the receiver and sealed within the annular chamber formed by the neck of the inlet 12 and flange 13 by means of a suitable plastic material such as paraffin or the like, indicated at 15. A dischargepipe 16 is connected with the upper end of receiver 12 and is also connected with an exhaust pump or other suitable means for withdrawing thegases which collect in the receiver 12.

Mounted on the upper flat surface of the concave bottom 2 of the tank is a deflector and supporting member 20, made of stoneware, glass or the like, provided with an annular flange 21 on its top, which is adapted to receive the base of a generally cylindrical anode 31, which latter is preferably made of graphitic carbon provided with longitudinal flutes on its side and terminating in a conical upper end. The lower end of the anode is fixed in the support 20 by means of a suitable cement 32.

Secured to the under face of the tank bottom 2 is a stufling box comprising an upper flanged section 22 bolted to the tank bottom, a lower telescoping flange section 25 which is adjustably secured to the upper flange 22 by means of bolts 27, said flanges inclosing two insulating ring members 23 and 24 between which a suitable insulating fibrou'spacking 26 is disposed as more particularly illustrated in Fig. 2. Fitted within the insulating-packing rings 23 and 24 is a cylindrical connector member 30;, preferably made of the same type of carbon as the anode 31, the upper end of which connector is tapered to fit a correspondingly tapered recess in the base of the anode 31. Suitable current leads 35 and 36 are connected .to terminal 30 and the outside wall of the tank respectively. o

Disposed about the conical base of the tank,-below the deflector plate 20, is' an annular manifold or supply he'ade'r42 provided with a series of discharge openings on its outer face, said manifold being connected to a supply pipe 40 which latter is controlled by a suitable valve 41, so that when water or other washing medium is supplied to the header it will be delivered in the form of a series of fine jets or streams directed towardthe inner wall of the tank 1 and thence upwardly between the tank wall and the liner 3. Near the upper rim of the tank 1, and opposite the outlet pipe 17, there is memes provided a discharge pipe 45 fitted with a suitable control valve 44. Near the bottom of the tank 1 a suitable discharge faucet 50 is provided from which the reaction products collected in the bottom of the tank are dlscharged.

It is to be understood, that instead of forming the anode 31 and connector member 30 as separate elements they may be constructed of a single iece of carbon, but in either. event it is deslrable thatthe portion of the anode which passes through the stuffing box be treated withparafiin or similar material which would prevent the carbon from absorbing the liquid in the tank and permitting the absorbed liquid to seep out by reason of the porosity of carbon.

The operation of the apparatus in electrolyzing a solution of sodium chlorid or brine, for example, is as follows. A relatively strong solution of brine is supplied to the tank and then a quantity of salt crystals is added through the inlet 12 until the level of the liquid in the tank rises above the lower end of the partition 5. This will also produce a submersion of the lower end of receiver 8 in the liq uid and salt crystals. ,1

Current is then applied, entering by way of the conductor 35 and passing through the anode 31 and the salt solution, thence to the liner 3 and the iron tank 1 and the conductor 36 back to the source. The effect of the current passing from the surface of the anode 31 through the liquid breaks up the sodium chlorid solution, liberating the chlorin which passes directly upward from the anode surface and collects in the receiver 8.

The liberated sodium which tends to pass to the cathode, represented by the wall of the tank 1, combines with the elements of the water present to form sodium hydrate or caustic soda, thereby liberating part of the hydrogen of the water at or adjacent to the cathode surface formed by the tank wall and the liner 3, which latter also forms a component part of the cathode. The perforations in the liner are effective in diverting the heavier caustic soda solution downward through the space between the liner and the tank wall, so the solution settles quietly and collects at the bottom of the tank without any material tendency to diffuse throughout the lighter brine solution. Furthermore, the tongues 4 on theliner, being in electrical contact with the cathode wall -1, arefefi'ective in preventing any material diminution of, the current which would normally be produced by the resistance of theheavier caustic soda solution adjacent to the cathode surface. The liberated hydrogen rises freely through the liquid adjacent to the liner, any portion of the gas formed between the liner and the tank wall 1 pass through the perforations in the liner, and the total volume of liberated hydrogen collecting in the annular space between the partition plate 5 and the imperforate upper section of liner 3. The operation of the pumps or other evacuating devices connected with the chlorin outlet 16 and the hydrogenoutlet 17 is so regulated that the degree of vacuum produced in the hydrogen space is never in excess of that produced in the top of receiver 8, so that the two gases are maintained effectively sepaaral'ed throughout the operation of the cell and are delivered therefrom in substantially pure condition. The relatively strong solution oi. caustic soda which collects at the bottom of the tank remains quiescent therein with little or no tendency to diffuse throughout the supernatant lighter salt solution, and is drawn off at the tap 50 as oocasion may require. a

It frequently occurswhen more or less impure salt or brine solutions or salt crys tals are employed that the impurities, which are usually present in the form of other compounds or solutions, will decompose at the surface of the anode, with the formation of other compounds, usually in the form of hydrates, which tend to collect at the surface of the cathode and thereby materially increase the internal resistance of the cell and commensurately diminish the efficiency of the latter. This is particularly true of the brine solutions and salt crystals which have been contaminated with magnesium chlorid, or bittern, which decomposes at the anode surface, with the result that the free magnesium combines with the water of the solution and forms magnesium hydrate, which collects (in the inner-wall of the tank 1 and very materially increases the-resistance to the passage of the electrical current. In order to overcome this diiliculty the header pipetQ is provided, so that when the valve ll in the water supply pipe 4L0 is opened a series of fine jets or streams of water is delivered radially againstthe tank walls and as the water is much lighter than the brine solution it rises in a rapid current hetween the tank wall 1 and the liner 3- and washes the surfaces free of the accumulated hit-tern or hydrate oi magnesium, which is discharged through the outlet p e The operation of the cell as dicated is continuous and requires only t e addition of salt crystals from timeto time to ma' thahrine sol t point of substantial saturation, yo l added through the st ly OPQHJHQ top of receiver 8 ano water plied throu h the p 10 and header l-Q. it will he understood, of course, normal operation the appaenis, the valves ll and are closed and the chlorin hydrogen pipes ill and i7 opened subject to the action of the pumps or other ejector appa tus to induce a negative and hydrogen og the ceiving spaces, to withdraw these gases as rapidly as they are formed, said pipes delivering the gases to appropriate receptacles.

What I claim is 1. An electrolytic cell comprising a tank constituting a cathode, an anode therein, a receiver supported from the top of the tank and immersed in the electrolyte surrounding the anode, and a perforated liner spaced from the inner wall of the tank.

2. An electrolytic cell comprising a tank constituting a cathode, an anode therein, a receiver supported from the top of the tank and immersed in the electrolyte surrounding the anode, and a perforated liner of similar material to the tank spaced from the inner wall of the latter and having multiple points of contact therewith.

3. An electrolytic cell comprising a tank constituting a cathode, an anode therein, a receiver supported from the top of the tank and immersed in the electrolyte surrounding the anode, a perforated liner spaced from the inner wall of the tank having an imperforate upper section sealed to the tank wall to provide an annular chamber, a valved outlet from said chamber, and a supply header located adjacent to the bottom of the tank wall to direct washing water between the wall and the liner.

l. An electrolytic cell comprising a tank constituting a cathode, an anode therein, a receiver supported from the top of the tank and immersed in the electrolyte sur rounding the anode, a perforated liner spaced from the inner wall of the tank having an imperforate upper "section sealed to the tank wall to provide an annular chamber, a valved outlet from aid chamber, and an annular supply header located. adjacent to the bottom of the tank wall to direct washing water between the wall and -the sealed to the top thereof and surrounding .1.

"' receiver, and gas outlets connected with receiver the space between the mdv the annular partition,

' electrolytic cell cor cathode, ,,:r s mported from he top of the decreed in ele trolyte sure anode, an annular partition om the tanlr w l and herrn sealed to the top then surrou.. 7 receiver, gas outlet connected with o- 'recuiver and the space hetween the tank "id the annular partition, and means -..t draw ng the gases from the receiver ular aftoresaid.

I the t e a tanlr anode therein,

5Q: Lee'meo 7. An electrolytic cell comprising a tank bottom of the tank through Which an ex- 10 constituting a cathode, a receiver mounted tension of theanode projects. on the top of the tank and immersed in the In testimony whereof I afiix my signa-. electrolyte, and an anode mounted in the ture, in presence of two witnesses.

bottom of the tank and projecting up- 1 Wardly toward the receiver; the mounting ELISHA BARTON for said anode comprising a flanged defiec- Witnesses:

tor plate in which the anode is seated, and MOLLIE J. ANDERSON,

an lnsula ing tufling box secured to the J. C. JACOBSON. 

